This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Forerunner 945 Public Beta 3.77 is now available



  • For any issues that you encounter please fill out the form included in the download and attach it to an email to [email protected]. Please note that you may not get a response to the email unless we need more information on the issue you report.
  • Although this software is believed to be reliable, it has not yet been released for production and should be used at your own risk.

Changes made from version 3.30 to 3.77:

  • Add Garmin Swim 2 Features: Advanced Swim Workouts, Auto rest, Critical Swim Speed, Swim Pacing Alerts
  • Added all-day respiration, respiration widget, and breathwork activity
  • Improved treadmill calibration
  • Added Pilates
  • Improvements to audio playback, audio apps
  • Fixed crash that could occur on activity save at high elevation
  • Fixed issue where sometimes heart rate and PulseOx data would not show when all-day PulseOx was enabled
  • Various other fixes and improvements

Installation Instructions

  1. Connect your Forerunner 945 to your computer using the USB cable.
  2. Download and unzip Place the GUPDATE.GCD file in the \GARMIN folder of your device's internal storage drive.
  3. In Forerunner945_377Beta, go to the RemoteSW folder. Place the GUP3114.GCD and GUP3303.GCD file in the \GARMIN\REMOTESW folder of your device's internal storage drive.
  4. Disconnect your device from the computer, approve the update on the watch, and wait for the update to finish.
  5. If you would like to revert to the last public release software, place the GUPDATE-330.GCD file in the \GARMIN folder. Rename GUPDATE-330.GCD to GUPDATE.GCD before disconnecting your device. To revert the RemoteSW, place the RemoteSW\Downgrades\GUP3114-270.GCD and RemoteSW\Downgrades\GUP-3303-430.GCD in the \GARMIN\REMOTESW folder. NOTE: If you revert to an older version of software, all of your settings will be reset to defaults.
  • Dumb question but what is DEM calibration? I always sleep with BT and WiFi turned off on my FR945. And being the phone 2 rooms away there is no chance they do any comminication during the night. What do I miss with this missing calibration?

  • It's not a dumb question at all. Garmin doesn't explain this well in the manual.  Anyway, if calibrate the altimeter not during an activity is turned on and you have a BT connection to your phone, the watch will use the phones GPS location and calibrate your altitude while in your sleep window. 

  • I think you mean DHM? 

    Is a digital map wich has the height of the locations in it. You can use this as a reference for the barometric altimeter, but it depends on the resolution. If your area is mostly flat in the place you are, its working good.
    If you are in a steep mountain side, I wouldn't trust it.

  • Where did you read that they use assisted GPS for that?

  • Can I ask a silly question; if I was to update / install Beta 3.77, when there was a stable update to 3.30, will my watch offer it up to me or would I be on the Beta upgrade branch of the FW tree?

    Also, if I install Beta 3.77 and then went back onto a stable release after 3.30, will I lose all my settings, or would it only be if I downgraded / went back to 3.30?

  • Beta is outbranched and needs always the manual installation as stated in the instructions. If there is a public release with a higher number, it will, depending on your settings, be installed automatically.

    If you downgrade, you will do a factory reset of the watch.

  • Yes for the 1st question - meaning you'll be notified and updated. There is no beta channel here, just manual beta testing.

    Yes for the 2nd quaestion - meaning downgrading is reseting the watch, but sync with the connect application should put all back in place.

  • Almost none of the settings is put back. Only the user settings like age, gender, weight. 
    Every App Setting, widgets, watch faces, connected sensors, Garmin pay, notification settings etc. need to be reentered on the watch.

  • I think you mean DHM? 

    It's DEM (digital elevation model).

    Where did you read that they use assisted GPS for that?

    We've improved the in-activity auto calibration for the altimeter by leveraging the DEM provided in our preloaded cartography data. Our new default is now “Continuous” mode (Settings > Sensors > Altimeter > Auto Cal. > During Activity). This continuous calibration setting enables an algorithm that uses both DEM and GPS elevation as references to offset any altimeter drift due to weather-related pressure changes during an activity. These improvements are provided in a long-term manner without sacrificing the main benefit of a separate altimeter sensor on the device: the ability to accurately track short-term elevation change and provide responsive elevation-related data during an activity (e.g. hill repeat workouts). Note: the At Start calibration also occurs when Continuous is enabled.

    We’ve added an altimeter calibration for watch mode as well (Settings > Sensors > Altimeter > Auto Cal. > Not During Activity). Assuming a user has enabled the use of location data on GCM, we will use the phone position along with the DEM provided in our preloaded cartography data to attempt a calibration each night during a user’s sleep window.

    It's been working great for me day 1, but I read where one user had an issue because it was calibrating his location at ground level and he lives on the 21st floor of his building.

  • I am not interested in trying the 3.77 beta right now, but can I use the included files to downgrade to 3.30 any time in the future? 3.30 fixed my battery issue so I want to have a downgrade option if the problem comes back in future updates.